Rotary impact pipe cutter



INVENTOR. .055,97 M 73420K BY fmwm #Mm TTfQ/VEYS.

R. M. D'ARCY ROTARY IMPACT PIPE CUTTER Mwah 28, i950 2 Sheets-Sheet 2 Filed Sept. 5, 1948 FVG.

F/G. 2E.

INVENTOR. EOEEET M. 0400 Patented Mar. 28, 1950 UNITED STATES PATENT VOFFICE RTARY IMPACT PIPE CUTTER Robert M. DArcy, Dallas, Tex.

Application September 3, 1948, Serial No. 47,635

3 Claims.

l n This invention relates to pipe cutters operated from within the pipe to be cut, and particularly to a pipe or casing cutter caused to rotate by delivering impacts to a portion thereof.

The main object of my invention is to provide a pipe or casing cutter for the casings of oil wells and the like which is capable of cutting the casing at a predetermined depth from within the casing by jarring the device or delivering a series of impacts thereto.

Another object is to provide means for positioning such a cutter in a selected position within the well casing or pipe and causing cutter means to project out into the cutting position with respect to said pipe.

A further object is to provide such a cutter with means for converting axial jarring and impact into controlled rotation of the cutter members in effective cutting direction.

It is also an object to have a cutter of the indicated character which is self-contained and effective to operate out in the eld without resort to makeshift or temporary expediente.

Other objects and advantages of my invention will appear in further detail as the specification proceeds.

In order to facilitate ready comprehension of this invention for a proper appreciation of the salient features thereof, the invention is illustrated ron the accompanying drawings forming part hereof, and in which:

Figure 1 is a vertical section through an oil well pipe or casing into which a rotary impact pipe cutter made according to the invention has been introduced preparatory to cutting off the length of said pipe or casing;

Figures 2a, 2b and 2c are all parts of a vertical section of the pipe cutter embodying the invention, being shown on an enlarged scale with Figure 2a showing the lowest section, 2b showing the intermediate section, and 2c showing the upper end or uppermost section of the pipe or casing cutter.

The same reference numerals indicate the same or like parts throughout.

In oil fields, it occasionally occurs that an oil Well becomes exhausted and useless, or for some reason the well is no longer used. As a well of this type is usually lined with a pipe or casing of metal, a deep well thus represents a considerable investment in metal in the casing. In fact, the casing, if in good condition, may largely be used again, and in any event, salvage of as much of the casing as possible is always desirable. Obviously, this means that the casing should be (Cl. 16d-0.4)

2 cut off as far down in the well as practicable, so that the portion thus cut off may be raised to the surface. Of course, I am aware that certain expedients have heretofore been tried, but results have been rather limited.

Upon considering this problem carefully, it has occurred to me that a purely rotary cutter to be lowered far down into an oil well casing is not practical, while on the other hand, if Vibration or jarring about or near the surface will suffice to cause a cutting action, it should be possible to out the pipe or casing at a much greater depth than has heretofore been possible, so that as much of the casing is salvaged as then becomes practical. As a result, I have found it quite feasible to produce a rotary impact pipe cutter which derives its rotation from direct impacts or jarring of one end thereof, as will now be described more fully.

Hence, in the practice of my invention, and referring again to the drawings, an oil well casing 3A extending down into the ground 4 is first provided with a location plug 5 of more or less conventional construction provided with a small bore i3 and with a pair of opposite grooves l, 1. Before describing the manner in which the present casing cutter is lowered into the tube or casing 3, it will perhaps serve best to described the device in detail.

As best seen in Figure 2a, at the lower end of the device is a feeder head 8 preferably conical in form and having an upper cylindrical portion 8 from which project a pair of radially-extending butteriiies or flanges I0, I0, the head being integral with an upwardly-extending shank II. The upper end of the shank II is threaded at l2 and screwed into a wedge or converter feed block i3. The wedge or converter feed block I3 is slidably disposed within a tool holder Id within the hollow interior of which are a pair of opposite verticle grooves E5, I5 into which a pair of lcorrespending ribs I6, It upon the block I3 project in slidable manner. At the lower end the tool holder has a reduced neck portion I'I, and this terminates at the bottom in a fiange I8. Beneath the lower end of the tool holder I4 is xed a collar i9 by means of a setscrew Zt upon the shank I I, the latter projecting rotatably through a bore 2i in the neck Il and into the interior of the tool holder within which a second collar 22 xed on the upper portion of the shank beneath the threaded portion I2 thereof by means of a set screw 23 rests rotatably on the bottom 2li of said interior. The shank II thus projects rotatably up through the bore 2| in neck Il of tool holder I4 and rotation thereof with respect to the tool holder will cause it to be gradually unscrewed from the block I3 with consequent raising of the block along the grooves i5, I5 in the interior 25 of said tool holder. The effect of such raising of block I3 will presently be noted in more detail. Surmounting the tool holder I4 is an upper tool holder 26 complementary to the lower tool holder I4 and having a large internal bore 21, while at the lower end thereof it is provided with a pair of radially-extending slots 28, 28 serving to locate and guide a pair of radially-extending cutting tools 29, 29, each of which has a pin 3U affixed thereon, both pins being interconnected by means of a tension spring 3I tending to draw the tools together within the outline of the tool holders I4 and 26. The latter are secured together by a group of long vertical bolts 32, 32, so that both tool holders together will serve as a toolholding unit. Within the inner chamber 25 of the IlowerV tool, holder I4 is located an upwardlypointed wedge -or converter 33 engaging slidably against a pair of inner inclined ends 34V of the cutting tools 219, 29, while the lower end 35 of the wedge 33 rests upon the feed block I3.

The arrangement is such that if the lower feeding head 8 9 is seated Vin the plug 5 within the casing 3, as per Figure 1, and the side anges or butterflies I0, I0 engage in the grooves 1, 1 to prevent the head from rotating, and then some means. is applied to the tool-holder assemblage to rotate the latter, it is' obvious that due to the fact that the feed block I3 will be forced to rotateA with. the tool-holder-assemblage due to its ribs I6, I6 engaging4 in the grooves I5, I5 within chamber 25 4of the lower tool holder, this block will gradually unscrew from the upper end I=2 of the shank I t, thereby gradually raising the block I3 and with it the wedge 33, which will, of course, gradually wedge the two cutting tools 29, 29 apart so that the outer ends thereof will engage against the sides of the well casing 3 and begin to cut into the same, and when such rotation is continued, the tools will be fed increasingly farther out untilA such feeding of the tools and simultaneous rotation will cause the casing to be cut through after but a few revolutions.

At this stagev attention is now to be directed to the means Afor causing rotation of the tool holder assembly for eifecting the mentioned cutting of the well casing. At the upper end of the upper tool housing or holder member 26, the bore 21 reduced to a smaller bore 36 providing a shoulder 31, and upon the upper end of the same member 26 is a rachet 38 capable of interengag- 'ing with a corresponding downwardly-projecting rachet 39 of an upper rotatable rachet section 4I). The two Vrachets 38` and 39 are retained in aligned assembly by means of a rachet clutch member 4I slidably fitting in the bore 3'6 within lower ratchet 38, the lower end of the clutch member 4I being provided with a head 42 normally engaging against the shoulder 31 and being prevented from dropping down into the bore 21 by means of a stop ring '43 vexpanded into a groove 44 in the wall of bore 21 but a short distance below said head 42. The upper end of the clutch member 4I is also provided with a cylindrical head 45 slidable in the bore 46 in the lower end of the upper clutch member 40, but at a predetermined point spaced below the head 45 is a cushioning collar of ber or other material 41 fixed within the bore 46 by means of a set screw 48 providing in the distance between the head 45 and the upper edge of said collar 41 ample clearance for 4 the clutch member 4I to be moved with the toolholder assembly downward to release the clutch members 38 and 39 temporarily from each other, this being a necessary part of the movement for operating the present casing cutter, as will appear later on.

Loosely surrounding the lower portion of the upper ratchet member 40 is a group of slip holders 49, 49 retained in association by means of a ring 5G secured thereto. Pivotally mounted at 5I, 5I upon the upper ends of the slip holders 49, 49 are a corresponding number of tubing slips 52, 52 provided with the gripping teeth 53, 53 upon the upper outer sides thereof, and at the lower ends provided with springs 54 enveloping the pivot members 5I engaging against the holders 49 and the lower portions of said members 52 in such fashion as to tend to swing the slips inward toward the clutch member 49. Cooperating with these slips is a lower tapered ring 55 slidably surrounding the intermediate portion of clutch member 40 and having a shoulder recess 56 about the upper end thereof to which is tted a tube 51, the lower end of which is secured to the tapered member 55 by means of screwsl 58, 5,8. The tapered hollow member 55 forms a slip expander upon the lower end of the tubular housing 51 and simultaneously a lower retainer for the upper ratchet member 4I) inasmuch as the latter is provided with an upper flange 59 for which the upper end 6I! of member 55 forms an effective stop, as best seen in Figure 2b. The mentioned tubular housing 51 extends upwardly a predetermined distance to terminate just below the upper end of the shank 6I to be further explained, and within said upper end of the housing is fixed a collar 62 within which a fiber seal or other material in the form of a washer or smaller collar 63 is located and slidably mou-nted on the mentioned shank 6I. At the lower end of shank 6I just mentioned is attached a housing 64 which is likewise tubular and within the lower end of which are secured a pair of inwardly-directed groove .runners 65, 65 by means of screws 66, from which the inwardly-projecting, groove-engagement members 61, 61 extend integrally into a pair of opposite helical grooves 68, 68 in the sides of an upwardly-extending feed shaft 69 extending rigidly from the upper end of the upper clutch member 40 above the upper flange 59 thereof and terminating at the upper end in a flange 10 having a range of movement almost the distance between the upper closed end 1I by which the shank 6I is connected to the tubular housing 64 .and the upper ends of the groove runners 65. The upper end of the mentioned shank 6I terminates in a threaded portion 12 adapted to be connected to a standard jarring device in. order to provide vertical jarring movements andA impacts to shank 6I and thereby to tubularl housing 64 with its` groove runners 65.

It is self-evident that vertical movement of the shank 6I and housing 64 with its mentioned groove runners 65 will be converted to rotary movements of the feed shaft 69m both directions due to the helical form of the 'groove 68.

If the apparatus ris now to be lowered into the well casing 3 in order to cut the same, the jarring device is, of course, connected to the threaded upper end 12 of shank 6I, the jarring device including a weighted jarring rod, while a wire line is connected to the cutter assemblage and the housings in order to lower the assemblage into the well, and when the proper depth has been determined, the housing 51 is allowed 'to come l:guenter to rest with its lower slip-expanding, conical portion 55 engaging against the inner sides 13 of the slip members 52, causing the teeth 53 upon each to engage in the wall of casing 3, so that housing 51 is held firmly immovable within the well casing. It is, of course, simultaneously determined that the lower locating head 8, 9 comes to rest on the plug previously located at the proper depth within the casing, and the two wings or flanges I0, IU caused to engage in the grooves 1, 1 in the interior 6 of the nut to prevent rotation thereof when the apparatus is substantially ready for operation. Upon the jarring device being started to transmit the impact thereof down through shank El, the groove runners within the lower end of tubular member B4 will be caused to ride downward in the grooves 68, 68 with their projections 61, G1 gradually rotating the feed shaft 59. The tubular member 64 is thus allowed to travel downward a distance within the tubular housing 51, meanwhile rotating feed shaft 69, as already mentioned, with the result that the tool holders it and 26 forming the tool-holder assemblage simultaneously rotated through the interengagement of ratchets 38v and 39, causing gradual unscrewing of the thread 22 on shank Il from within the feed block i3 and consequent rise of the wedge 33' and separation of the cutting tools 29, 29 and projection thereof radially out through the slots 28, 28 to begin to out into the wall of casing 3. One descent of the tubular member B4 will only produce limited rotation of the feed shaft 69 so that the shank 6I with the jarring device and tubular member til are again raised causing reverse rotation of feed shaft 69 with simultaneous raising of the ratchet member lill, and with it separation of ratchets 38 and 39 and the raising of internal collar l1 against the bottom of the head 35 on the upper end of clutch member 4|, with the result that the reverse rotation is not transmitted to the tool-holder assemblage. Subsequently, the shank Bl and tubular member 34 are again allowed to descend, also allowing feed shaft 69 and the upper clutch member 40 connected to the bottom thereof to lower so that the clutch members 38 and 39 again become engaged, and jarring of the upper shank 5| will again cause the inner tubular housing 64 to descend with its groove runners 64 and 65 and their projections 61, 61 in the groove 68 again taking effect to rotate feed shaft 69, with consequent further rotation of the tool-holder assemblage and tools 29 and further feeding of the latter outward while cutting into the wall of well casing 3. This raising and lowering of the mentioned upper shank 6l and its internal housing 54 is repeated until a suiiicient number of revolutions of the toolholder assemblage i4, 26 with tools 29, 29 has occurred to completely cut through the casing 3. Preparatory to removing the cut portion of the casing, the cutting device thus far described must, of course, be raised and completely removed from the casing.

Obviously, when the housing 51 has raised, as well as the shank El, the lower conical end 55 of housing 51 will be drawn up out of contact with slips 52, allowing the teeth 53 thereof to disengage from the sides of the housing.

It should be mentioned at this point that during the cutting operation which has, of course, proceeded to the point where the cutting tools 29 have completely cut through the well casing, the wedge or converter which is actually a iioating` member has, of course, been gradually f edupward 6k until the sides 14, 14 have actually passed, the lower inner inclined faces 34 of the tool members 29, so that the upper inclined surfaces 15, 15 of said cutting tools will begin to engage the lower inclined surfaces 16, 16 of the wedge member 33, and due to the presence of spring 3l, the cutting tools 29 will be drawn together and the wedger forced upward into the bore 21 of upper tool holder 26. This action, of course, withdraws the tools 29 within the outline of the tool-holder assemblage I4 and 26 and allows the entire cutter assembly to be withdrawn from well casing 3.

Should I desire to do so, I may add further slips to engage within the tubular casing 3, and, of course, the proportions and arrangements of the parts may be varied so long as the jarring -principle of dropping the weights along the length of the jars and transmitting the impacts to the upper shank 5I is maintained. Thus, the downward movement of the inner housing 54 causes rotation of the feed shaft which is transmitted to the tool holders and the tools with the effect of cutting the casing of the well. .A

Manifestly, variations other than those noted may be resorted to and parts and features may be modified or used without others within the scope of the appended claims.

Having now fully described my invention, l claim:

1. A rotary impact pipe cutter adapted for insertion into the pipe or casing to be cut, including a pair of tool-holder members secured together one above the other in axial alignment to form a rotatable tool-holder assembly, the lower toolholder member having an upwardly-open, central chamber with vertical guide grooves in the sides thereof, the upper tool-holder member having a downwardly-open central chamber communicating with the central chamber of the lower toolholder member, the tool-holder assembly having a pair of opposite cutting tool slots extending radially outward from the resulting hollow interior therein, a .pair of cutting tools disposed radially slidable in the slots with the inner ends thereof extending into said hollow interior, a verticallymovable feed block located in the central chamber of the lower tool-holder member with projections extending slidably into the 4guide grooves therein, the feed block having a downwardly-open, threaded axial hole therein and said lower toolholder member having a vertical central bore through the lower end aligned with the threaded axial hole of the feed block, a shaft forming a shank having a guide means upony the lower end for engaging with a placing plug or the like to prevent rotation thereof and extending rotatably up through said vertical central bore and having the upper end threaded and engaging in the threaded hole in said feed block, a pair of stop members fixed upon the shank above and below the lower end of said lower tool-holder member to prevent axial movement of said shank with respect to said lower tool-holder member, an upwardly-directed wedge or converter supported upon said feed block with the apex portion disposed between the inner ends of said cutting tools in effective position to feed them radially outward from the tool-holder assembly against the casing to cut the latter upon rotation of said tool-holder assembly upon said shank, a spring biasing both tools inwardly toward each other to withdraw them into the outline of said tool-holder assembly when said feed block has been at least partly unscrewed from the upper threaded end of said shaft and has raised said wedge vupwardly past the .iu-

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ner ends of said cutting tools into the bore of the upper tool-holder member, a one way ratchet upon the upper end of the latter, an upper corresponding ratchet member adaptedl to engage with the one-way ratchet, an axial lost-motion connection between the ratchet and upper ratchet member allowing limited axial separation of the one from the other, an upwardly-extending feed shaft projecting rigidly from the upper end of said upper ratchet member and having helical grooves cut upon the feed shaft, a verticallymovable tubular member surrounding the latter, a pair of groove runners secured upon the inside of the latter movable tubular member having projections slidably engaging in the helical grooves in said feed shaft, and an upwardly-extending shank fixed upon the upper end of said movable tubular member and having the upper end thereof threaded for connection with a jarring device in order to cause downward travel of said movable tubular member about said feed shaft and travel of the groove runners along the helical grooves in the latter to cause a one-way rotation of said feed shaft and consequent rotation of said toolholder assembly through the ratchet and upper ratchet member.

2. A rotary impact pipe cutter adapted for insertion into the pipe or casing to be cut, including a pair of tool-holder members secured together one above the other in axial alignment to form a rotatable tool-holder assembly, the lower toolholder member having an upwardly-open, central chamber with vertical guide grooves in the sides thereof, the upper tool-holder member having a downwardly-open central chamber communicating with the central chamber of the lower tool-holder member, the tool-holdei' assembly having a pair of opposite cutting tool slots extending radially outward from the resulting hollow interior therein, a pair of cutting tools disposed radially slidable in the slots with the inner ends thereof extending into said hollow interior, a vertically-movable feed block located in the central chamber of the lower tool-holder member with projections extending slidably into the guide grooves therein, the feed block having a downwardly-open, threaded axial hole therein and said lower tool-holder member having a vertical central bore through the lower end aligned with the threaded axial hole of the feed block, a shaft forming a shang having a guide means upon the lower end for engaging with a placing plug or the like to prevent rotation thereof and extending rotatably up through said vertical central bore and having the upper end threaded and engaging in the threaded hole in said feed block, a pair of stop members fixed upon the shank above and below the lower end of said lower tool-holder member to prevent axial movement of said shank with respect to said lower tool-holder member, an upwardly-directed wedge or converter supported upon said feed block with the apex portion disposed between the inner ends of said cutting tools in effective position to feed them radially outward from the toolholder assembly against the casing to cut the latter upon rotation of said tool-holder assembly upon said shank, a spring biasing both tools inwardly toward each other to withdraw them into the outline of said tool-holder assembly when said feed block has been at least partly unscrewed from the upper threaded end of said shaft and has raised said wedge upwardly past the enner ends of said cutting tools into the bore ofthe upper tool-holder member, a one-way ratchet upon the upper end of the latter, an upper corresponding ratchet member adapted to engage with the one-way ratchet, the ratchet having an upwardly-open bore of smaller diameter than the main bore in said upper tool-holder member and the upper ratchet member also having a downwardly-directed bore therein, a ratchet-connecting member extending down into the upwardly-open bore in the ratchet and having a ange upon the lower end forming a retaining means within the main bore in said upper toolholder member, the ratchet-connecting member extending up into the downwardly-directed bore in said upper ratchet member and having a flange upon the upper end thereof which is axially slidable in the same bore, a stop collar secured in the lower portion of the latter bore about said ratchet-connecting member and serving as a cushion member and stop for limiting downward movement of said ratchet-connecting member to provide ample clearance for separation of the ratchet and upper ratchet member, an upwardly-extending feed shaft projecting rigidly from the upper end of said upper ratchet member and having helical grooves cut upon the feed shaft, a vertically-movable tubular member surrounding the latter, a pair of grooved runners secured upon the inside of the latter movable tubular member having projections slidably engaging in the helical grooves in said feed shaft, and an upwardly-extending shank xed upon the upper end of said movable tubular member and having the upper end thereof threaded for connection with a jarring device in order to cause downward travel of said movable tubular member about said feed shaft and travel of the groove runners along the helical grooves in the latter to cause a one-way rotation of said feed shaft and consequent rotation of said tool-holder assembly through the ratchet and upper ratchet member.

3. A rotary impact pipe cutter adapted for insertion into the pipe or casing to be cut, including a pair of tool-holder members secured together one above the other in axial alignment to form a rotatable tool-holder assembly, the lower toolholder member having an upwardly-open, central chamber with vertical guide grooves in the sides thereof, the upper tool-holder member having a downwardly-open central chamber communicating with the central chamber of the lower toolholder member, the tool-holder assembly having a pair of opposite cutting tool slots extending radially outward from the resulting hollow interior therein, a pair of cutting tools disposed radially slidable in the slots with the inner ends thereof extending into said hollow interior, a verticallymovable feed block located in the central chamber of the lower tool-holder member with projections extending slidably into the guide grooves therein, the feed block having a downwardlyopen, threaded axial hole therein and said lower tool-holder member having a vertical central bore through the lower end aligned with the threaded axial hole of the feed block, a shaft forming a shank having a guide means upon the lower end for engaging with a placing plug or the like to prevent rotation thereof and extending rotatably up through said vertical central bore and having the upper end threaded and engaging in the threaded hole in said feed block, a pair of stop members fixed upon the shank above and below the lower end of said lower tool-holder member to prevent axial movement of said shank with 75 respect to said lower tool-holder member, an up- Wardly-directed Wedge or converter supported upon said feed block with the apex portion disposed between the inner ends or" said cutting tools in effective position to feed them radially outward from the tool-holder assembly against the casing to cut the latter upon rotation of said toolholder assembly upon said shank, a spring biasingboth tools inwardly toward each other to withdraw them into the outline of said tooleholder assembly when said feed block has been at least partly unscrewed from the upper threaded end of said shaft and has raised said wedge upwardly past the inner ends of said cutting tools into the bore o the upper tool-holder member, a one-way ratchetl upon the upper end of the latter, an upper corresponding ratchet member adapted to engage with the one-way ratchet, an axial lostmotion connection between the ratchet and upper ratchet member allowing limited axial separation of the one from the other, an upwardly-extending feed shaft projecting rigidly from the upper end of said upper ratchet member and having helical grooves cut upon the feed shaft, a vertically-movable tubular member surrounding the latter, a pair of groove runners secured upon the inside of the latter movable tubular member having projections slidably engaging in the helical grooves in said feed shaft, an upwardly-extending shank fixed upon the upper end of said movable tubular member and having the upper end thereof threaded for connection with a jarring device in order to cause downward travel of said movable tubular member about said feed shaft and travel of the groove runners along the helical grooves in the latter to cause a. one-way rotation of said feed shaft and consequent rotation of said tool-holder assembly through the ratchet and upper ratchet member, a stop iiange upon the upper end of the upper ratchet member, a tubular guide housingr surrounding said flange and the helically-grooved feed shaft, a guiding collar Within the upper end of the tubular guide housing slidably engaging the upper shank upon the tubular member below the upper threaded end thereof, the slidable downwardly-tapered tubular member located upon said upper ratchet member and secured to the lower end of the tubular guide housing, and a plurality of slips surrounding the lower end of said upper ratchet member having the upper portions thereof extending upwardly exteriorly upon the downwardly-tapered tubular member and having a plurality of casing-engagement teeth upon the upper ends thereof for engaging the Well casing, the arrangement being such that when the tubular guide housing is lowered, the conical or downwardly-tapered tubular member thereof will wedge the slips outwardly in order to cause the teeth thereof to engage firmly with the interior of the well casing and prevent axial shift of said tubular guide housing.

ROBERT M. DARCY.

No references cited. 

